Obviously, I want to filter this view, to show only requests where responsible_user_referent is current user-> currently logged user can only see his own requests. This domain works fine, but I want to allow admin to see all requests in system. Is this possible and how? Currently admin can only see his own requests, like every other user...

It's pseudo code, not complete code, I just gave you direction. In order to get worked above code, you could add computed(functional) integer field, named as 'superuser_id', and it's computing function should return always SUPERUSER_ID (i.e. 'superuser_id' field should be computed to SUPERUSER_ID). In openerp/odoo you can import SUPERUSER_ID as follows: from openerp import SUPERUSER_ID. Separated menu that you've done also good workaround, cheers